Country Fire Authority (CFA) trucks raced to the blaze late yesterday afternoon on the Mailors Flat-Koroit Road which was threatening to burn into hundreds of hay bales and nearby cypress trees.

“Our firefighters were quick to pull it up before it got into them,” Warrnambool CFA incident controller Henry Barton said, averting a fire potentially lasting several days.

“It was really good work by everyone out there.” Fire investigators from Victoria Police and the CFA arrived at the scene to determine the cause of the blaze, which is still unknown.

“It’s being treated as suspicious, but all fires are treated as suspicious until we can determine the cause,” Mr Barton said.

It was a similar story across the south-west yesterday with firefighters preventing other spot fires from taking hold as temperatures spiked to 40 degrees late in the afternoon.

Grass fires around Portland and Jancourt flared up during the day but were suppressed.

Heywood DSE deputy incident controller Michael Harper said a fire burnt less than a hectare on Heath Road in Cashmore yesterday morning.

“It was reasonably quick, it started at 11.40am and was controlled by 12.40pm,” Mr Harper said.

The cause of the blaze had not been determined.

About 50 firefighters remained stationed around the Kentbruck bushfire nearby, which has burnt through another 900 hectares inside the controlled zone.

“That’s putting up a fair bit of smoke which will be visible over the next day,” Mr Harper said.

Severe weather conditions caused flare-ups several kilometres inside the containment zone. Mr Harper said there was some alarm yesterday as winds pushed the smoke column low to the ground towards Heywood and Narrawong. With little rain forecast for the coming week, he warned smoke would continue to blanket the region.

“The weather will cool off over the weekend but there’s not much rain predicted.

Speed restrictions still apply to the Portland-Nelson Road.

Meanwhile, a grass fire on private property in Jancourt East left five hectares scorched.

A spokeswoman for the Colac incident control centre said four crews from Cobden and Jancourt East had the fire under control on Naylors Road.